I'm not sure what oil you are using but try PB Blaster, good stuff. Also try to sand around the center hub with some sandpaper. When you get it off, apply a light coat of grease around the center hub.
Do the drums have a couple of threaded holes in them? If so, thread the proper size metric bolts into the holes and tighten. to not tighten too much because you can crack the drum face. With them tightened, hit the drum with a hammer.
The drums on my first gen Runners all have threaded holes for that very reason. Just drive in a couple of bolts and they come right off. I was told about the holes by a certified Toyota master mechanic. Works every time.